"Dominant Process" test and multicore.

[Dubolomov]

Hi.
In my solution "dominant process" test checks process only on one core of two dualcore processor system. So i have 4 cores. Does this test can checks mean value of all CPU cores of the system?

[KS-Soft Europe]

Strange. "Dominant process" test uses WMI (Win32_Process class), so everything should work smoothly.
Could you start "WMI Explorer", and perform the following query: Select * from Win32_Process
Do you see all processes? Or just processes that are running on one CPU?

Regards,
Max

[Dubolomov]

Yes, i see all process on local system (where WMI explorer was started).
I'm using "Dominant Process" test for remote hosts. I saw result of process with 125% of CPU load. After this i looked on that remote server and saw that this process using only one CPU core. So this process couldn't take 100% of all CPUs (4 cores).

[KS-Soft]

Sorry for delay. We have checked our code looking for mistake, everything looks fine. May be we misundertand the problem? Or may be there is no problem at all?

In my solution "dominant process" test checks process only on one core of two dualcore processor system.

Why do you think so? HostMonitor and Task Manager shows different CPU usage for the process?

I'm using "Dominant Process" test for remote hosts. I saw result of process with 125% of CPU load. After this i looked on that remote server and saw that this process using only one CPU core

Why process uses just one CPU core? Have you assigned specific CPU for this process using Processor Affinity option?
In such case all threads of the process shold be executed by specified CPU, but I am not so sure about Windows kernel. HostMonitor checks total cpu usage (user time + kernel) time and probably kernel may use other CPU as well..

Regards
Alex

[Dubolomov]

For example right now i see result of this test is "103:EXCEL.EXE".

Code: Select all

; ------- Test #2941 -------

Method      = DominantProcess
;--- Common properties ---
;DestFolder = somedestfolder\
LinkedTo    = somefilderforlink\
Title       = sometestname
Comment     = somecomments
RelatedURL  = 
ScheduleMode= Regular
Schedule    = 
Interval    = 60
Alerts      = E-Mail on4
ReverseAlert= No
UnknownIsBad= No
WarningIsBad= Yes
UseWarning  = Yes
WarningExpr = (%FailureIteration% > 0) and (%FailureIteration% < 4)
UseCommonLog= No
PrivateLog  = somelogfile--%yyyymmdd%--log.txt
PrivLogMode = Full
CommLogMode = Default
SyncCounters= Yes
SyncAlerts  = No
DependsOn   = list
MasterTest-Alive = somemastertest
;--- Test specific properties ---
Host        = 192.168.0.10
Threshold   = 75
CheckMode   = CPU Usage
DisplayMode = ValueName

Yes, i see different CPU usage in TaskManager and HostMonitor. But i see the same result in TaskManager and WMI test "select PercentProcessorTime from Win32_PerfFormattedData_PerfOS_Processor".

[KS-Soft]

Yes, i see different CPU usage in TaskManager and HostMonitor. But i see the same result in TaskManager and WMI test "select PercentProcessorTime from Win32_PerfFormattedData_PerfOS_Processor".

Of course HostMonitor's Dominant Process test will show results different from Win32_PerfFormattedData_PerfOS_Processor.PercentProcessorTime.
Dominant Process tells you CPU load caused by single process (process that uses the most of system resources). While WMI counter PercentProcessorTime shows total CPU Usage by all processes on the system (100% - system idle process)

Regards
Alex

[Dubolomov]

Dominant Process tells you CPU load caused by single process (process that uses the most of system resources).

Ok. So i can't see persent of full CPU load that uses most powerfull process through Dominant Process test. Right?

[KS-Soft Europe]

So i can't see persent of full CPU load that uses most powerfull process through Dominant Process test. Right?

No, it is not correct. "Dominant" process test shows you process (and CPU usage % for this process), that the CPU that is really utilized most of processor time.
In previous post, Alex just wanted to point you out that Win32_PerfFormattedData_PerfOS_Processor class shows the CPU Usage of certain processor (CPU) or total CPU usage over all processors in your system. "Dominant Process" test shows you the CPU Usage utilized by certain process. You may see this value in "Processes" tab of "Task Manager" applet.
BTW. Could you try to setup the script, described in the following post: http://www.ks-soft.net/cgi-bin/phpBB/vi ... php?t=4498
This script calculates "CPU usage %" for certain process in another way.
You just should "catch" the moment when dominant process test will show you the wrong value (125% or so) and see, what value is shown by this new script. Could you try that?

Regards,
Max

[Dubolomov]

I think that this script can't help because i have few citrix servers where i'm try to find powerfull process. It can be any process with the same name.

[KS-Soft]

Could you please clarify why do you think Dominant Process test shows wrong value?
1) You said "I saw result of process with 125% of CPU load" - this can be correct value if you have 2 or more processors. There are 4 CPU cores on your system, theoretically test may return up to 400%
2) Next time you referred to Win32_PerfFormattedData_PerfOS_Processor class but this WMI class has nothing to do with specific process (it shows total CPU usage). That's why it shows different value.
Probably I do not understand something but I do not see evidences.

Regards
Alex

[Dubolomov]

Could you please clarify why do you think Dominant Process test shows wrong value?

Because how any proces can take 172% of CPU? I see now such process on one of the server. It is "services.exe".

1) You said "I saw result of process with 125% of CPU load" - this can be correct value if you have 2 or more processors. There are 4 CPU cores on your system, theoretically test may return up to 400%

Yes! So now i know that dominant process shows load of only one core, not all cores of CPU(s).

2) Next time you referred to Win32_PerfFormattedData_PerfOS_Processor class but this WMI class has nothing to do with specific process (it shows total CPU usage). That's why it shows different value.
Probably I do not understand something but I do not see evidences.

Yes. I mean that WMI class test shows realy load of full processor(s) with all cores. So i just want to know what value shows this test, all system or only one core.

Thank you.

[KS-Soft]

Because how any proces can take 172% of CPU? I see now such process on one of the server. It is "services.exe".

1 process may start hundreds of threads. 100 threads may be executed on 100 processors. So, 1 process can be executed on 100 processors and use 100%x100processors=10,000% (just for example)

Yes! So now i know that dominant process shows load of only one core, not all cores of CPU(s)

No. Dominant Process shows how much processor time is used by "dominant" process. If this process is executed on several processors, you will see total CPU usage.

Regards
Alex

[Dubolomov]

Ok, thank you.